Species dispersal rates alter diversity and ecosystem stability in pond metacommunities

摘要: Metacommunity theory suggests that relationships between diversity and ecosystem stability can be determined by the rate of species dispersal among local communities. The predicted relationships, however, may depend upon relative strength environmental processes disturbance. Here we evaluate role frequency predation perturbations in affecting patterns pond plankton metacommunities. Pond metacommunities were composed three mesocosm communities: one communities maintained constant "press" from a selective predator, bluegill sunfish (Lepomis macrochirus); second community conditions without predation; third experienced recurrent "pulsed" sunfish. triads connected at either no, low (0.7%/d), or high (20%/d) planktonic dispersal. Richness composition zooplankton biomass productivity measured regional spatial scales. Dispersal significantly affected such biotas greatest number species. unimodal dispersal-diversity relationship was predator-dependent, as press excluded regardless Further, there no effect on beta because generated selected for distinct assemblages. Spatial temporal responded to but not predation. Low destabilized producer stabilized productivity. results indicate prevent augmentation mass effects has apparent influence stability. rates, contrast, have significant both multiple scales